1. Field of the Invention
The present invention relates to systems for analyzing the characteristics of thermal energy relative to a space, for recognizing the presence of a person in the space, and for determining whether or not the person is experiencing a physical emergency.
2. Description of the Prior Art
Understanding of the present invention rests on the distinction between occupant status and occupancy status. Occupancy status is concerned with establishing whether a given space is occupied. Occupancy status systems are typically employed to detect intrusion or to control environmental factors. Occupant status is focused on the disposition of the occupant, once his or her presence in a given space has been established. For example, occupant status involves identifying whether a person present in a space is experiencing a possible emergency or is in a normal physical state. Furthermore, occupant status may entail determining how the person, when in a normal state, is relating to the space, i.e., whether he or she is willing to be disturbed and whether his or her absences from the space are for a short or a long duration. Making such determinations necessitates the sensing of two or more of the physical attributes (physical state indicia) of the person relative to the designated space and analyzing them separately and jointly (the process of sensor fusion). Occupant status may also include displaying a unique signal for each physical condition identified.
Several methods are known for manually signaling the wish not to be disturbed or the need for assistance by a person present in a given space as representatively disclosed by Winston (see, U.S. Pat. No. 3,964,058), Perka, et al. (see, U.S. Pat. No. 6,104,942) and Wagner, et al. (see, U.S. Pat. No. 6,236,303). However, these methods are limited by the possibility that the person present in the space may be unable to perform the manual activity required to activate the desired signals or may neglect to do so.
Various methods are also known for employing a single motion sensor to detect occupancy in a space as representatively disclosed by Kamada (see, U.S. Pat. No. 4,679,034), Myllymaki (see, U.S. Pat. No. 5,640,141), and Vories, et al. (see, U.S. Pat. No. 5,861,806). However, these methods cannot reliably detect the presence of a person in a designated space since they may be activated by motion outside the designated space or by motion within the space that is caused by a source other than a person. Moreover, these methods cannot determine occupant status since they consider only one aspect of a person""s behavior, namely motion. These same limitations are found in the multiple-sensor systems such as disclosed by Baldwin, et al. (See, U.S. Pat. No. 5,971,597), which employs a motion sensor to detect occupancy and other types of sensors to detect light and temperature for the purpose of controlling a building""s electrical and/or mechanical systems.
Several methods are known for using multiple motion sensors to detect the occupancy of a space as representatively disclosed by Fowler (see, U.S. Pat. No. 6,078,253), Katz, et al. (see, U.S. Pat. No. 6,188,318), Wang (see, U.S. Pat. No. 6,211,783) and Myron, et al. (see, U.S. Pat. No. 6,222,191). While the employment of multiple motion sensors may produce more reliable occupancy status by reducing the incidence of false triggering, the concentration on motion alone precludes the making of determinations about occupant status. Additionally, several methods are known for employing multiple motion sensors arranged to stratify the reception of input from a given space as representatively disclosed by Tomooka, et al. (see, U.S. Pat. No. 5,703,368) and Dwight, et al. (see, U.S. Pat. No. 5,905,436). These systems may be able to detect when a person""s motion is confined to the lower level of reception. However, they cannot determine the physical status of the person since they lack the ability to detect whether the motion being evidenced from the lower level of reception is normal or abnormal and, most importantly, to detect when the person is present but not moving. Methods are also known for utilizing motion sensing and/or thermal sensing to determine human occupancy in a given space as disclosed by Morinaka, et al. (see, U.S. Pat. No. 5,877,688), Akagawa, et al. (see, U.S. Pat. No. 6,137,407), and Rechsteiner, et al. (see, U.S. Pat. No. 6,246,321). While these methods utilize cross-technology sensors to make detection of human occupancy more certain, they do not employ sensor fusion to make determinations about the status of the occupant.
Finally, several methods are known for employing sensors that embody differing technologies and sensor fusion to determine the status of a passenger in an automobile and to activate an air bag as representatively disclosed by Adolf, et al. (see, U.S. Pat. No. 5,785,347), Corrado, et al. (see, U.S. Pat. No. 6,026,340), and Breed, et al. (see, U.S. Pat. No. 6,081,757). However, these methods do not determine multiple passenger conditions or employ indicators to signal information about the passenger""s status. Rather, they gather passenger data solely to confirm the presence of parameters related to deploying an airbag in a crash.
Consequently, a need still remains for an occupant status monitor that utilizes cross-technology sensors and sensor fusion to detect the presence of a person in a space, to determine the physical status of that person relative to the space, to provide a unique signal reflective of each status both locally and remotely, and to allow the person to forestall the activation of unwanted occupant status signals and to activate selected occupant status signals manually as a personal security and time management aid.
An occupant status monitor, according to the present invention, comprises three components. A detector, preferably utilizing passive infrared technology, senses the temperature range, size, shape, motion, time, and position of thermal energy in and relative to a space and transmits data concerning one or more of these parameters. A processor receives the data transmitted by the detector, compares the transmitted data with a predetermined data set representing attributes of a person or of the space, and transmits instructions based upon the results of the comparison. An indicator receives the instructions from the processor and activates signals showing whether a person is occupying or has occupied the space and the status of an occupant relative to the space.
In one embodiment, the processor instructs the indicator to activate a first occupant status signal when a person occupying the space is experiencing a possible physical emergency. The processor instructs the indicator to activate a second occupant status signal when a person occupying the space is not experiencing a possible physical emergency. The processor instructs the indicator to activate a third occupant status signal when a person has vacated the space briefly within a predetermined time period. The processor instructs the indicator not to activate a signal when no person is occupying the space during a time outside of the predetermined time period.
A variation of the second occupant status signal may be activated to show that the person occupying a given space is unwilling to be disturbed. A variation of the third occupant status signal may be activated to show when a person has vacated the space for a long duration during a predetermined time period.
Preferably, the processor is a microcomputer housed in a control module, which can also contain means for manually instructing the indicator to activate or deactivate occupant status signals and means for replicating the visual portion of those signals. Preferably, the indicator comprises a tone generator and an array of three lights. Typically, the three lights are red, amber, and green in color, where the red light and an audible tone are activated for the first occupant status signal, where the green light is activated for the second occupant status signal, where the amber light is activated for the third occupant status signal, and where no light or tone is activated for the fourth occupant status signal.
In one embodiment of the invention, activating occupant status signals is confined to the indicator. In yet another embodiment of the invention, activating occupant status signals is performed by a personal computer in the designated space using on-screen graphics and an internal tone generator. In yet another embodiment of the invention, the indicator shares activation of occupant status signals with a personal computer located in the space.
In one embodiment of the invention, the control module is a stand-alone component. In yet another embodiment of the invention, communications, processing and control functions are performed entirely by a personal computer located in the space.
In one embodiment of the invention, the control module or personal computer may be connected to a communications network, to allow for occupant status signals being activated at the immediate location to be replicated at remote locations by indicators and/or personal computers and/or illuminated panels linked to the same network and for occupant status signals being activated at remote locations to be replicated by the local indicator and/or personal computer. In yet another embodiment of the invention, personal computers that are connected to the same communications network may be used by a person to enter manual instructions for signals concerning his or her own status to be activated by the indicator and/or personal computer at his or her workstation while he or she is absent from the space.
Additionally, a concealed switch, connected to the control module or personal computer, may be used to send a silent alert to selected remote locations by means of a communications network.
In another aspect of the invention, the parameter detected by the detector is temperature and the predetermined data set includes a value representing a minimum temperature indicative of fire danger. Thus, when the temperature parameter data exceeds the predetermined data set value, the instruction sent by the processor will cause the indicator to activate the first occupant status signal as a fire alarm.